[202511] BROADCOM_LEGACY_SAI_COMPAT: Fix sai_query_stats_st_capability crash on Tomahawk-1 (BCM56960)

[lipxu]

Why I did it

On Arista 7060cx (BCM56960_B1 / Tomahawk-1, broadcom-legacy platform), syncd crashes at startup with a SIGSEGV inside brcm_sai_st_pd_ctr_cap_list_get+0x10 when running SONiC 202511 images.

Root cause: sairedis commit 4f1d7d99 (PR #1700) restored sai_query_stats_st_capability to AC_CHECK_FUNCS in configure.ac. Because all Broadcom builds share XGS SAI headers (buildimage issue #23387), HAVE_SAI_QUERY_STATS_ST_CAPABILITY=1 is defined for all Broadcom platforms including broadcom-legacy. On TH1, the SAI library initializes p_pdapi_st=NULL (no streaming telemetry hardware on TH1), but brcm_sai_st_pd_ctr_cap_list_get dereferences it without a null check — SIGSEGV.

This is a 202511 backport of the fix already merged into master via sonic-sairedis PR #1788 + sonic-buildimage master PR #26013.

Work item tracking

• Microsoft ADO (number only):

How I did it

Add SAI_STATS_ST_CAPABILITY_SUPPORTED=0 to sai.profile for all 5 Arista 7060cx HWSKU variants (BCM56960/Tomahawk-1). The runtime guard in syncd (sairedis PR #1788, now in 202511 via PR #1790) reads this key during apiInitialize() and nulls the query_stats_st_capability function pointer, causing VendorSai::queryStatsStCapability() to return SAI_STATUS_NOT_IMPLEMENTED — same behavior as before the regression.

Files changed (5):

• device/arista/x86_64-arista_7060_cx32s/Arista-7060CX-32S/sai.profile
• device/arista/x86_64-arista_7060_cx32s/Arista-7060CX-32S-C32/sai.profile
• device/arista/x86_64-arista_7060_cx32s/Arista-7060CX-32S-D48C8/sai.profile
• device/arista/x86_64-arista_7060_cx32s/Arista-7060CX-32S-Q24C8/sai.profile
• device/arista/x86_64-arista_7060_cx32s/Arista-7060CX-32S-T96C8/sai.profile

Each file gets:

# BROADCOM_LEGACY_SAI_COMPAT: TH1 (BCM56960) has no streaming telemetry platform driver;
# sai_query_stats_st_capability crashes in brcm_sai_st_pd_ctr_cap_list_get.
SAI_STATS_ST_CAPABILITY_SUPPORTED=0

How to verify it

1. Build broadcom-legacy SONiC image for 202511 with this PR + sairedis 202511 PR [platform] Accton: As5712-54x correct driver id for dumping DDM of sfp+ ports #1790
2. Boot on Arista 7060cx (BCM56960_B1)
3. Confirm syncd starts without crash: show logging | grep -i sigsegv → no output
4. Confirm key is read: show logging | grep SAI_STATS_ST_CAPABILITY_SUPPORTED → disabling query_stats_st_capability for this platform
5. Confirm counters work normally

Which release branch to backport (provide reason below if selected)

• 202305
• 202311
• 202405
• 202411
• 202505
• 202511

Tested branch (Please provide the tested image version)

Description for the changelog

Add SAI_STATS_ST_CAPABILITY_SUPPORTED=0 to sai.profile for Arista 7060cx (BCM56960/Tomahawk-1) to prevent syncd SIGSEGV crash at startup on broadcom-legacy 202511 images.

Link to config_db schema for YANG module changes

N/A

A picture of a cute animal (not mandatory but encouraged)

🐧

[mssonicbld]

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